Surface adhesion and its dependence on surface roughness and humidity measured with a flat tip
- 作者：Arzu Ç ; olak ; a.colak@utwente.nl ; Herbert Wormeester ; Harold J.W. Zandvliet ; Bene Poelsema
- 关键词：Adhesion force ; Capillary force ; Surface roughness ; Relative humidity ; Flat tip
- 刊名：Applied Surface Science
- 出版年：2012
- 期刊代码：6_01694332
- 类别：ms
- 出版时间：1 July, 2012
- 卷：258
- 期：18
- 页码：6938-6942
- 文件大小：739 K
摘要
The adhesion force between a surface and the tip of an atomic force microscope cantilever has been determined by recording force-distance curves with an atomic force microscope. Flat tips with a diameter of 2 渭m were used to mimic the adhesion between two parallel surfaces. In such a configuration, the location for the formation and breaking of the capillary water neck is a stochastic by nature, significantly different from that of a spherical tip. The adhesion force is measured as a function of relative humidity for smooth and chemically etched Si(1 0 0) surfaces. The roughness of the etched substrate reduces the adhesion by more than an order of magnitude, depending on the exact value of the relative humidity. The adhesion force increases with increasing humidity until a relative humidity of about 70%. Beyond a relative humidity of 70%a decrease of the adhesion force is observed. We anticipate that the latter is due to a decrease of the cross section of the water neck at the snap off point with increasing relative humidity.